title: Visceral pleural invasion does not affect recurrence or overall survival among patients with lung adenocarcinoma ≤ 2 cm: a proposal to reclassify T1 lung adenocarcinoma.
abstract: BACKGROUND
  T1 (≤ 3 cm) tumors with visceral pleural invasion (VPI) are upstaged to T2a (stage IB) in the TNM classification. We investigated the effect of VPI on the cumulative incidence of recurrence (CIR) and overall survival (OS) of lung adenocarcinoma (ADC) ≤ 2 cm (T1a) and 2 to 3 cm (T1b).
  
  
  METHODS
  OS and CIR among patients with or without VPI were examined by tumor size (≤ 2 and 2-3 cm) in 777 patients with node-negative lung ADC ≤ 3 cm who underwent resection.
  
  
  RESULTS
  Among patients with tumors ≤ 2 cm, VPI was not associated with either increased CIR (P = .90) or decreased OS (P = .11). Among patients with tumors 2 to 3 cm in size, the presence of VPI was associated with increased CIR (P = .015) and decreased OS (P &lt; .001), even after adjusting for histologic subtype. When stage I lung ADCs ≤ 3 cm were regrouped as either new stage IA (≤ 2 cm with or without VPI, 2-3 cm without VPI) or new stage IB (2-3 cm with VPI), there was a statistically significant difference in 5-year CIR and OS between new stage IA and new stage IB tumors (CIR, 18% vs 40% [P = .004]; OS, 76% vs 51% [P &lt; .001]).
  
  
  CONCLUSIONS
  VPI stratifies prognosis in patients with lung ADC 2 to 3 cm but not in those with tumors ≤ 2 cm. Our proposed regrouping of a new stage IB better stratifies patients with poor prognosis, similar to published outcomes in patients with stage II disease, who may benefit from adjuvant chemotherapy.
authors.affiliation: Division of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Nitadori
authors.affiliation: Division of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Christos
authors.initials: C
authors.lastname: Colovos
authors.affiliation: Division of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Kyuichi
authors.initials: K
authors.lastname: Kadota
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Camelia S
authors.initials: CS
authors.lastname: Sima
authors.affiliation: Division of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Inderpal S
authors.initials: IS
authors.lastname: Sarkaria
authors.affiliation: Division of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Nabil P
authors.initials: NP
authors.lastname: Rizk
authors.affiliation: Division of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: Valerie W
authors.initials: VW
authors.lastname: Rusch
authors.affiliation: Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY.
authors.forename: William D
authors.initials: WD
authors.lastname: Travis
authors.affiliation: Division of Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY; Center for Cell Engineering, Memorial Sloan-Kettering Cancer Center, New York, NY. Electronic address: adusumip@mskcc.org.
authors.forename: Prasad S
authors.initials: PS
authors.lastname: Adusumilli
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D009367:Neoplasm Staging; D009518:New York / Q000453:epidemiology; D010994:Pleura / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate / Q000639:trends; D055815:Young Adult